Работа с XML в lua

XML to JSON(table)

local mxj=require("pkg/mxj")
local resJson,ers,ern=mxj.XmlToJson(res)
if resJson.Envelope.Body.Fault~=nil and  resJson.Envelope.Body.Fault.faultstring~=nil  then
     return "", resJson.Envelope.Body.Fault.faultstring,4
end